/* APPLE LOCAL file libstdc++ debug mode */ // Safe sequence/iterator base implementation -*- C++ -*- // Copyright (C) 2003 // Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 2, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. #ifndef _GLIBCXX_DEBUG_SAFE_BASE_H #define _GLIBCXX_DEBUG_SAFE_BASE_H namespace std { namespace __debug { class _Safe_sequence_base; /** \brief Basic functionality for a "safe" iterator. * * The %_Safe_iterator_base base class implements the functionality * of a safe iterator that is not specific to a particular iterator * type. It contains a pointer back to the sequence it references * along with iterator version information and pointers to form a * doubly-linked list of iterators referenced by the container. * * This class must not perform any operations that can throw an * exception, or the exception guarantees of derived ierators will * be broken. */ class _Safe_iterator_base { public: /** The sequence this iterator references; may be NULL to indicate a singular iterator. */ _Safe_sequence_base* _M_sequence; /** The version number of this iterator. The sentinel value 0 is used to indicate an invalidated iterator (i.e., one that is singular because of an operation on the container). This version number must equal the version number in the sequence referenced by _M_sequence for the iterator to be non-singular. The version number is used for fast invalidation and to aid in undoing iterator invalidations after an exception. */ unsigned int _M_version; /** Pointer to the previous iterator in the sequence's list of iterators. Only valid when _M_sequence != NULL. */ _Safe_iterator_base* _M_prior; /** Pointer to the next iterator in the sequence's list of iterators. Only valid when _M_sequence != NULL. */ _Safe_iterator_base* _M_next; protected: /** Initializes the iterator and makes it singular. */ _Safe_iterator_base() : _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0) { } /** Initialize the iterator to reference the sequence pointed to by @p__seq. @p __constant is true when we are initializing a constant iterator, and false if it is a mutable iterator. Note that @p __seq may be NULL, in which case the iterator will be singular. Otherwise, the iterator will reference @p __seq and be nonsingular. */ _Safe_iterator_base(const _Safe_sequence_base* __seq, bool __constant) : _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0) { this->_M_attach(const_cast<_Safe_sequence_base*>(__seq), __constant); } /** Initializes the iterator to reference the same sequence that @p __x does. @p __constant is true if this is a constant iterator, and false if it is mutable. */ _Safe_iterator_base(const _Safe_iterator_base& __x, bool __constant) : _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0) { this->_M_attach(__x._M_sequence, __constant); } ~_Safe_iterator_base() { this->_M_detach(); } public: /** Attaches this iterator to the given sequence, detaching it * from whatever sequence it was attached to originally. If the * new sequence is the NULL pointer, the iterator is left * unattached. */ void _M_attach(_Safe_sequence_base* __seq, bool __constant); /// Detaches this iterator from the sequence it is attached to, if any. void _M_detach(); /** Determines if we are attached to the given sequence. */ bool _M_attached_to(const _Safe_sequence_base* __seq) const { return _M_sequence == __seq; } /** Is this iterator singular? */ bool _M_singular() const; /** Can we compare this iterator to the given iterator @p __x? Returns true if both iterators are nonsingular and reference the same sequence. */ bool _M_can_compare(const _Safe_iterator_base& __x) const; }; /** * @brief Base class that supports tracking of iterators that * reference a sequence. * * The %_Safe_sequence_base class provides basic support for * tracking iterators into a sequence. Sequences that track * iterators must derived from %_Safe_sequence_base publicly, so * that safe iterators (which inherit _Safe_iterator_base) can * attach to them. This class contains two linked lists of * iterators, one for constant iterators and one for mutable * iterators, and a version number that allows very fast * invalidation of all iterators that reference the container. * * This class must ensure that no operation on it may throw an * exception, otherwise "safe" sequences may fail to provide the * exception-safety guarantees required by the C++ standard. */ class _Safe_sequence_base { public: /// The list of mutable iterators that reference this container _Safe_iterator_base* _M_iterators; /// The list of constant iterators that reference this container _Safe_iterator_base* _M_const_iterators; /// The container version number. This number may never be 0. mutable unsigned int _M_version; protected: // Initialize with a version number of 1 and no iterators _Safe_sequence_base() : _M_iterators(0), _M_const_iterators(0), _M_version(1) { } /** Notify all iterators that reference this sequence that the sequence is being destroyed. */ ~_Safe_sequence_base() { this->_M_detach_all(); } /** Detach all iterators, leaving them singular. */ void _M_detach_all(); /** Detach all singular iterators. * @post for all iterators i attached to this sequence, * i->_M_version == _M_version. */ void _M_detach_singular(); /** Revalidates all attached singular iterators. This method * may be used to validate iterators that were invalidated * before (but for some reasion, such as an exception, need to * become valid again). */ void _M_revalidate_singular(); /** Swap this sequence with the given sequence. This operation also swaps ownership of the iterators, so that when the operation is complete all iterators that originally referenced one container now reference the other container. */ void _M_swap(_Safe_sequence_base& __x); public: /** Invalidates all iterators. */ void _M_invalidate_all() const { if (++_M_version == 0) _M_version = 1; } }; } // namespace __debug } // namespace std #endif /* _GLIBCXX_DEBUG_SAFE_BASE_H */